Carbon Monoxide

Carbon monoxide (CO) is a gas made up of carbon and hydrogen. It is naturally present in the air in varying amounts. It is odourless, invisible, highly poisonous and dangerous.

Where does carbon monoxide come from?

The carbon monoxide found in the air comes from several sources:

• Natural sources

CO is naturally present in the atmosphere and is emitted by ecosystems such as the oceans, volcanoes, forests, marshes, etc. Fires and forest fires also produce carbon dioxide. Living organisms themselves emit carbon dioxide when breathing.

• CO: a combustion residue

The main source of carbon monoxide in towns and cities is road traffic. Industrial activity such as oil refineries, the metal industry, incinerators and pulp factories also emit CO.

• Domestic sources of CO

There are also several causes for the presence of carbon monoxide indoors. Although pollution from outside road traffic can seep into the home, CO in an enclosed space is usually caused by smoking or heating devices. Devices that work by burning fuel (wood, coal, oil or gas) release CO into the air in the home. Heating and cooking appliances are particularly liable to emit carbon dioxide, which is the residue of incomplete combustion. If this type of device is defective or used incorrectly, this burning process releases CO in excessive quantities, posing a real health threat.

Carbon monoxide: the number one cause of fatal poisoning in France

Carbon monoxide poses a major health threat. Because it's highly toxic, regular exposure at low doses causes serious and long-term health problems and like many volatile organic compounds (VOC) it can be responsible for chronic illnesses and cancer.
However, the health risks go much further. Excessive levels of carbon monoxide can cause severe poisoning and even death. Every year, more than 300 people die and several thousand are poisoned due to carbon monoxide exposure. CO is the number one cause of deaths from poisoning in France and most cases of exposure to this deadly gas occur in the home.

Why does carbon monoxide poisoning happen?

The main problem with CO is that even though it's highly poisonous, it's odourless, invisible and therefore can't be detected by people in an indoor space. What's more, poisoning occurs very quickly and victims don't always have enough time to identify the symptoms before this gas proves fatal. The effects can be similar to other illnesses and may not immediately arouse suspicion.

Once inhaled, carbon monoxide replaces the oxygen in the blood by attaching itself to the red blood cells and can cause fatal poisoning in less than an hour. A low amount of this gas is enough to have a significant health impact, with 0.1% of CO in the air being sufficient to cause fatal poisoning. In addition, because this gas spread very rapidly, potential victims need to react very quickly. Discover all our products

What causes excessive levels of this fatal gas?

According to France's national health monitoring institute ("Institut de veille sanitaire"), at least eight in ten cases of poisoning take place in the home, and a defective boiler is the most common cause. Although all domestic heating appliances give off small quantities of CO, intensive or inappropriate use or a lack of maintenance are a factor in emitting dangerous doses.

If a water heater or a gas, wood, oil or coal-fired heating appliance isn't working properly, the oxygen input is insufficient and the combustion process is incomplete, causing CO to be released instead of CO2. An oven or stove may also be responsible, although most accidents and poisonings occur during the winter, when the interior of a home is being heated more often.

Symptoms of poisoning

The symptoms of poisoning are difficult to identify, as they are similar to other illnesses and can be misleading about the cause of the problem. Because asphyxia of the blood occurs, the respiratory symptoms occur later than you might think.
Take action quickly if the people in a space, either adults or children, experience symptoms such as a headache, nausea, vertigo or impaired vision. Excessive tiredness, vomiting or feeling sick are also signs of poisoning and require a fast reaction and decision-making.

How can you avoid carbon monoxide poisoning?

• Preventing poisoning

To protect the health and safety of inhabitants, you need to be following certain rules in the home. Simple safety rules allow you to prevent poisoning, notably by ensuring that potentially dangerous devices are used safely. Heating systems, water heaters and flues must be checked every year by a professional. Also remember to properly ventilate your home, particularly rooms where these types of appliances are located. It's also essential to regularly clean the ventilation systems to refresh the oxygen in a room. Never block the air vents, even to save on heating, as this can pose a health risk.

Read and follow the instructions for heating appliances. For example, additional heating devices must not be run continuously. Lastly, never use a device for heating a room that isn't designed for this purpose (stove, barbecue, etc.) and never operate power generators indoors. By following these simple prevention and safety instructions you can reduce the potential risk to the health and life of the people in your home.

• What should you do in case of poisoning?

If adults or children fall victim to this type of poisoning, you need to react quickly, as their life is in danger. The first thing to do is vent the place where the gas has spread and switch off the boiler or other appliances you think might be responsible. Air the room as much as possible to dilute and vent the poisonous gas and call the fire service or an ambulance as soon as possible.

Affected individuals can only recover if they are quickly attended to by firemen, then in hospital. Even if the exposure was short or you merely suspect poisoning, you must go to a hospital. The health or even life of an exposed child or adult could be at risk. A blood sample is taken to establish a diagnosis and provide the appropriate treatment. This involves placing the victim of CO exposure into a hyperbaric chamber in order to breathe oxygen at high pressure. This treatment with oxygen, which is only provided in hospital, is the only effective way to restore oxygen in the blood.

Should you fit a carbon monoxide detector in your home?

Protecting the health and safety of your loved ones is a priority. To prevent accidents and the risk of illness linked to CO2 exposure, it's best to install a detector as a preventive measure. If CO2 levels pose a health risk, an audible alarm is triggered to alert you.
Installing this device in the correct place, in the room where the potentially dangerous appliances are located, will allow you to react quickly and limit the exposure in other living areas such as children's bedrooms. For optimal prevention, get a detector that complies with the European standard NF EN 50291.

However, it's important to note that this type of detector can't prevent accidents entirely, and you'll still need to make sure your appliances are properly maintained. Lastly, remember to vent living areas every day to limit your exposure to this risk and protect everyone's health. The Netatmo Healthy Home Coach can also help you with this task: by alerting you when CO2 levels rise in a room, it reminds you to vent it regularly to refresh the ambient air.